U.S. patent application number 10/199468 was filed with the patent office on 2004-01-22 for hygienic electric toothbrush.
This patent application is currently assigned to Chiaphua Industries Limited. Invention is credited to McNair, John Duncan.
Application Number | 20040010870 10/199468 |
Document ID | / |
Family ID | 30443310 |
Filed Date | 2004-01-22 |
United States Patent
Application |
20040010870 |
Kind Code |
A1 |
McNair, John Duncan |
January 22, 2004 |
Hygienic electric toothbrush
Abstract
A bristle head for an electric toothbrush has a casing, a drive
shaft within the casing and a flexible membrane mounted to or
formed integrally with the casing. A number of bristle tufts extend
from the flexible membrane and roots of each tuft extend into the
casing. A transmission is provided for transmitting movement of the
drive shaft to the roots of the bristle tufts whereupon the
flexible membrane flexes as or the bristle tufts move. The design
prevents toothpaste and other liquid from entering into the casing
where it might wear moving parts and harbour bacteria.
Inventors: |
McNair, John Duncan; (Hong
Kong, HK) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
700 THIRTEENTH ST. NW
SUITE 300
WASHINGTON
DC
20005-3960
US
|
Assignee: |
Chiaphua Industries Limited
2 Dai Wang Street, Tai Po Industrial Estate
Tai Po
HK
|
Family ID: |
30443310 |
Appl. No.: |
10/199468 |
Filed: |
July 22, 2002 |
Current U.S.
Class: |
15/22.1 |
Current CPC
Class: |
A61C 17/22 20130101;
A61C 17/222 20130101 |
Class at
Publication: |
15/22.1 |
International
Class: |
A61C 017/22 |
Claims
1. A bristle head for a toothbrush, comprising: a casing, a drive
shaft within the casing, a flexible membrane mounted to or formed
integrally with the casing, a plurality of bristle tufts extending
from the flexible membrane, and transmission means for transmitting
movement of the drive shaft to said bristle tufts whereupon the
flexible membrane flexes as the bristle tufts move.
2. Be bristled head of claim 1, wherein the bristle tufts pass
through the flexible membrane.
3. The bristle head of claim 1 further comprising an activator base
into which roots of the bristle tufts beneath the flexible membrane
are received.
4. The bristle head of claim 3, wherein the activator base includes
followers that bear against the drive shaft.
5. The bristle head of claim 4, wherein the drive shaft includes an
offset crank portion with which the followers engage.
6. The bristle head of claim 4, wherein the drive shaft includes a
cam portion with which the followers engage.
7. The bristle head of claim 3, wherein a number of said activator
bases are provided alongside one another, each associated with a
subset of said bristle tufts, and each adapted to pivot
independently upon interaction with the drive shaft.
8. The bristle head of anyone of the preceding claims being formed
integrally with an electric toothbrush having a handle housing a
battery and a motor and a neck securing the bristle head
thereto.
9. The bristle head of any one of claims 1 to 7 being a replaceable
attachment for an electric toothbrush.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to electric toothbrushes. More
particularly, although not exclusively, the invention relates to an
electric toothbrush having bristles activated to move by a
mechanism sealed within the bristle head that is isolated from
water, toothpaste and bacteria.
[0002] Most electric toothbrushes have gaps between moving parts
nearby the bristles at the bristle head. These gaps provide
passages through which abrasive toothpaste can pass into the
mechanism, causing wear. Also, if saliva and bacteria enter the
bristle head through those passages, such can remain inside the
bristle head, thereby providing an internal breeding ground for the
bacteria. Thorough rinsing of the bristle head exterior has little,
if any effect in reducing what remains inside to fester. This is
clearly an unhygienic, and therefore undesirable state of
affairs.
OBJECTS OF THE INVENTION
[0003] It is an object of the present invention to overcome or
substantially ameliorate the above disadvantage and/or more
generally to provide an improved electric toothbrush bristle
head.
[0004] It is a further general object of the present invention to
provide an electric toothbrush bristle head having a bristle-moving
mechanism sealed therein and thereby isolated from liquid.
[0005] Another object of the present invention is to provide an
electric toothbrush bristle head having bristles extending through
a flexible membrane, which flexible membrane acts as a pivot
mounting for the bristles.
DISCLOSURE OF THE INVENTION
[0006] There is disclosed herein a bristle head for a toothbrush,
comprising:
[0007] a casing,
[0008] a drive shaft within the casing,
[0009] a flexible membrane mounted to or formed integrally with the
casing,
[0010] a plurality of bristle tufts extending from the flexible
membrane, and
[0011] transmission means for transmitting movement of the drive
shaft to said bristle tufts whereupon the flexible membrane flexes
as the bristle tufts move.
[0012] Preferably the bristle tufts pass through the flexible
membrane.
[0013] Preferably the bristle head further comprises an activator
base into which roots of the bristle tufts beneath the flexible
membrane are received.
[0014] Preferably the activator base includes followers that bear
against the drive shaft.
[0015] Preferably the drive shaft includes an offset crank portion
with which the followers engage.
[0016] Alternatively, the drive shaft can include a cam portion
with which the followers engage.
[0017] Preferably a number of said activator bases are provided
alongside one another, each associated with a subset of said
bristle tufts, and each adapted to pivot independently upon
interaction with the drive shaft.
[0018] Preferably the bristle head is formed integrally with an
electric toothbrush having a handle housing a battery and a motor
and a neck securing the bristle head thereto.
[0019] Alternatively, the bristle head can be a replaceable
attachment for an electric toothbrush.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A preferred form of the present invention will now be
described by way of example with reference to the accompanying
drawings, wherein:
[0021] FIG. 1 is a schematic part cross-sectional perspective
illustration of a bristle head in an inverted orientation,
[0022] FIG. 2 is a schematic inverted perspective illustration of
parts of the bristle ahead of FIG. 1,
[0023] FIG. 3 is a schematic parts-exploded inverted perspective
illustration of the bristle head of FIG. 1,
[0024] FIG. 4 is a schematic parts-exploded perspective
illustration of the bristle head of FIG. 1,
[0025] FIG. 5 is a schematic plan view of the bristle head of FIGS.
1 to 4,
[0026] FIG. 6 is a schematic cross-sectional elevational view of
the bristle-head taken at VI-VI in FIG. 5,
[0027] FIG. 7 is a schematic cross-sectional elevational view of
the bristle-head taken at VII-VII in FIG. 6,
[0028] FIG. 6 is a schematic cross-sectional elevational view of
the bristle-head taken at VI-VI in FIG. 6,
[0029] FIG. 7 is a schematic cross-sectional elevational view of
the bristle-head taken at VII-VII in FIG. 6,
[0030] FIG. 8 is a schematic cross-sectional elevational view of
the bristle-head taken at VIII-VIII in FIG. 6, and
[0031] FIG. 9 is a schematic cross-sectional elevational view of
the bristle-head taken at IX-IX in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] In the accompanying drawings there is schematically depicted
a bristle head 10 for an electric toothbrush. The bristle head 10
is typically made of moulded hard plastics material such as, but
not limited to ABS, or polypropylene and includes a number of
bristle tufts 11 passing through a flexible membrane 12. Flexible
membrane 12 is formed of resilient plastics material, such as, but
not limited to TPE (synthetic rubber), Latex, natural rubber, or
any flexible, appropriately strong and durable material.
[0033] The flexible membrane 12 is attached securely and sealed to
a casing 13 formed of moulded plastics material. The casing 13 is
formed integrally with a neck 14. The flexible membrane 12 has a
periphery 27 that can be fitted tightly to the casing to form a
sealed engagement therewith. Alternatively, the periphery 27 of the
flexible membrane can be glued, plastics-welded or otherwise sealed
to the casing. As yet a further alternative, the flexible membrane
12 could extend the whole way about the casing 12 to thereby encase
it. It could even extend around the neck 14, or at least a portion
thereof.
[0034] Extending longitudinally through the neck 14 is a drive
shaft 19. Beneath the bristle tufts 11, the drive shaft 19 includes
an offset crank portion 15. The distal end 26 of the drive shaft 19
is located within an aperture formed in the casing 13. This
aperture need not pass the whole way through the casing 13.
[0035] The flexible membrane 12 has a number of holes 21 through
which individual bristle tufts 11 pass. Holes 21 and bristle tufts
11 are so dimensioned that a fluid-tight seal is formed between the
membrane and the bristle tufts.
[0036] The bottom ends or "roots" of the bristle tufts are received
within respective activator bases 17 positioned directly behind the
flexible membrane 12. Glue or sealant can be provided amongst
and/or about the bristles at the root of each tuft to seal against
the flexible membrane and/or in holes formed in each activator base
within which the roots are received.
[0037] There are three activator bases 17 in the depicted
embodiment. With reference to FIG. 4, the activator bases 17 extend
in a length-wise direction of the bristle head and are separated
from one another by longitudinal gaps 22. The activator bases 22
are typically formed of moulded plastics material in a single die.
To this end, two thin bridges 20, one at each end of the activator
bases, remain from plastics-flow passages in the die and can stay
in place in the finished product upon severing of thin legs 26.
These thin legs also remain from further flow passages in the die.
Alternatively, the bridges 20 can be discarded.
[0038] Each activator base 17 has formed integrally therewith one
or more followers 18. The centre-most activator base 17 can have a
pair of followers 18 inbetween which the crank portion 15 of drive
shaft 19 passes. Each of the outboard activator bases 17 can have a
follower 18 to bear against the crank portion 15. These outboard
followers 18 extend into a recess 29 formed in the centre-most
activator base 17. Because of this recess 29, there is a missing
tuft block 25 as shown in FIG. 1.
[0039] A coloured ring 30 can be attached about the base of the
neck 14 to aid in identifying the apparatus as that of a particular
individual.
[0040] In use, the drive shaft 19 is continuously rotated or
pivotally oscillated back and forth about its longitudinal axis by
a motor in a toothbrush handle from which the neck 14 extends. As a
result, the eccentric crank portion 15 bears against the followers
18 to cause the followers to move laterally back and forth. The
holes 21 where the bristle tufts pass through the flexible membrane
serve as hinge points for the bristle tufts. The bristle tufts will
therefore pivot about axes, which extend parallel to the
length-wise longitudinal axis of the bristle head. In the depicted
embodiment, each activator base and its associated bristles will
pivot in unison.
[0041] During use of the bristle head, the crank portion and other
internal moving parts are protected from toothpaste and other
liquid, as there is nowhere for the same to enter the casing.
[0042] It should be appreciated that modifications and alterations
obvious to those skilled in the art are not to be considered as
beyond the scope of the present invention. For example, instead of
a continuous crank portion 15, individual cams having their lobes
pointing in different directions, or shorter crank portions
extending in different radial directions can be employed to thereby
cause the individual activator bases and associated bristles to
oscillate differently from one another.
* * * * *